[Crex]

Lots of info here most good some bad. Heating to anneal in a wood stove or bonfire is an iffy thing at best. Yellow hot is way to hot especially on thin sawblade steel. Creating more problems with both grain growth and carbon burn out (notice the big scales when removed from the ashes? not a good thing). Your best be there is to wait until the fire is out and you are down to hot coals, slip the steel in under the coals in the ashes and leave over night.
Careful temp controlled annealing is important in thinner material. And as mentioned above, you will have to reheattreat the steel.

If you can cut the steel with a cold chisel, it is most likely too soft to make a serious quality blade. You need to look into reheattreating the steel for good performance.

A lot of the old two man crosscuts (we called them "misery whips" or "gator backs" growing up) were actually only partially hardened - the cutting edge/teeth. Pretty much an edge-quench kind of thing, so the back is usually a good bit softer. Can make a big diff when cutting out a blade you don't intend to heattreat.

Good thing is most were made out of good hi-carb steel and can be made into decent knives with proper heattreating. Lot of nice dimension (thickness) steel to work with that is a shame to waste. While I agree wholeheartedly with Ray on starting with known steel such as 1084, I am not against recycled steel use. Do it all the time, just a lot more to it than meets the eye. Heck of a bigger learning curve and a whole bunch of testing - retesting - and testing again.

Cheap HB sidegrinder with metal cut-off disc would be the quickest and easiest method to cut out blade blanks. It can also be used to profile and set initial bevels with practice. Fast and dirty but very efficient. Wear safety glasses and gloves, do it outside.

Lot of you guys are missing the boat by not filling out your profile. You might be living just down the road from some of us and can get some "hands-on" help with your learning curve. Worth the extra effort.